持续低量有机肥与化肥配施对绿洲农田土壤肥力和多功能性的影响

Effects of Sustained Low Level Organic Fertiliser and Chemical Fertiliser Blending on Soil Fertility and Multifunctionality inOasis Farmland

摘要:

由于干旱区有机肥数量有限，需明确低量有机肥与化肥配施对绿洲农田土壤理化性质、微生物群落及多功能性的影响程度，确定有机肥的最适用量。于2021—2023年在新疆沙雅县海楼镇开展田间试验，试验共设四个处理：NPK（单施化肥）、NPK+OM3（3 000 kg?hm-2牛粪+化肥）、NPK+OM6（6 000 kg?hm-2牛粪+化肥）和NPK+OM12（12 000 kg?hm-2牛粪+化肥）。采用高通量测序（16S rRNA和内源转录间隔区（ITS））技术，测定分析有机肥施用量对土壤理化性质、微生物群落组成及多样性的影响程度，探讨土壤多功能性对有机肥用量的响应。结果表明：（1）连续3年施用低量有机肥（NPK+OM3）显著增加了土壤有机碳（SOC）、全氮（TN）、有效磷（AP）、速效钾（AK）和硝态氮（NO3--N）含量，除pH之外的其他指标NPK+OM3处理与NPK+OM6处理差异不显著；（2）NPK+OM6和NPK+OM12处理土壤细菌（Chao1和香农（Shannon）指数）和真菌（Shannon指数）α多样性显著提高，细菌群落结构发生显著改变；（3）随着有机肥施用量增加，芽单胞菌门（Gemmatimonadota）、酸杆菌门（Acidobacteria）和球囊菌门（Mortierellomycota）的相对丰度增加，而放线菌门（Actinobacteria）和绿弯菌门（Chloroflexi）的相对丰度降低；（4）施用有机肥通过改变土壤养分和pH来改变细菌群落组成和多样性，进而提高土壤多功能性。综上所述，连续三年施用有机肥（3 000~6 000 kg?hm-2）可通过提高土壤养分含量、改善微生物群落组成和多样性将土壤多功能性维持在较高水平。考虑到有机肥数量有限和施肥成本，在绿洲农田作物生产中，施用3 000~6 000 kg?hm-2有机肥可达到提升土壤多功能性的效果。

Abstract:

【Objective】The usage of organic fertilizers in arid zones is limited, which necessitates investigating the most suitable amount required for optimum agricultural productivity, and clarifying the degree of influence on soil physicochemical properties, microbial communities, and multifunctionality in oasis farmland when applied in low amounts in combination with chemical fertilizers.【Method】A field experiment was conducted in Hailou Town, Shaya County, Xinjiang from 2021 to 2023. High-throughput sequencing (16S rRNA and endogenous transcribed spacer region) technology was used to determine and analyze the extent of the effects of organic fertilizer application on soil nutrient physicochemical properties, microbial community composition, and diversity, and to explore the response of soil multifunctionality to organic fertilizer dosage. Four treatments were set up: NPK (chemical fertilizer only), NPK + OM3 (3 000 kg?hm-2 cattle manure + chemical fertilizer), NPK + OM6 (6 000 kg?hm-2 cattle manure + chemical fertilizer), and NPK + OM12 (12 000 kg?hm-2 cattle manure + chemical fertilizer).【Result】The results showed that: (1) Application of organic manure significantly increased soil organic carbon, total nitrogen, available phosphorus, available potassium and nitrate nitrogen, and significantly decreased soil pH; (2) NPK + OM6 and NPK + OM12 treatments significantly increased microbial (Chao1 and Shannon index) and fungal (Shannon index) diversities, and significantly changed the community structure; (3) The relative abundance of Blastomonas, Acidobacilli and Glomus increased, but that of Actinomycetes and Campylobacter decreased with the increase in manure application rate; (4) The application of organic fertilizer can change the composition and diversity of bacterial community by changing soil nutrients and pH, thereby improving soil versatility.【Conclusion】Soil nutrients and microbial community composition and diversity increased significantly with the increase of organic manure application. Three years of organic manure application (3 000-6 000 kg?hm-2) could maintain soil multifunctionality at a high level by increasing soil nutrient content and improving microbial community composition and diversity. Considering the limited amount of organic fertilizer and the cost of fertilization, the application of 3 000-6 000 kg?hm-2 organic fertilizer in crop production in oasis farmland can achieve the effect of improving the multi-function of soil.